<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
    *{margin: 0;padding: 0}
    li{
        list-style: none;width: 100px;
        line-height: 50px;text-align: center;
    }
    li{float: left}
    .row:after{
        content: "";
        display: table;clear: both;
    }
    .nav{background: pink;}
    a{
        text-decoration: none;color: #333;
    }
    .drop{
        position: relative;
    }
    .drop-content{
        width: 100px;text-align: center;
        position:absolute;
        display: none;
        background: salmon;
    }
    .drop:hover .drop-content{
        display: block;
    }
    .drop-content a{display: block}
    </style>
</head>
<body>
    <ul class="nav row">
        <li class="drop">
            <a href="#">收藏夹</a>
                <div class="drop-content">
                    <a href="#">收藏宝贝</a>
                        <a href="#">收藏店铺</a>
                </div>
        </li>
        <li><a href="#">卖家中心</a></li>
        <li><a href="#">联系客服</a></li>
    </ul>
</body>
</html>